From: Arnaldo Carvalho de Melo <[email protected]>

Circa v5.2 this started to fail:

  # perf trace -e /wb/augmented_raw_syscalls.o
  event syntax error: '/wb/augmented_raw_syscalls.o'
                       \___ Operation not permitted

  (add -v to see detail)
  Run 'perf list' for a list of valid events

   Usage: perf trace [<options>] [<command>]
      or: perf trace [<options>] -- <command> [<options>]
      or: perf trace record [<options>] [<command>]
      or: perf trace record [<options>] -- <command> [<options>]

      -e, --event <event>   event/syscall selector. use 'perf list' to list 
available events
  #

In verbose mode we some -EPERM when creating a BPF map:

  # perf trace -v -e /wb/augmented_raw_syscalls.o
  <SNIP>
  libbpf: failed to create map (name: '__augmented_syscalls__'): Operation not 
permitted
  libbpf: failed to load object '/wb/augmented_raw_syscalls.o'
  bpf: load objects failed: err=-1: (Operation not permitted)
  event syntax error: '/wb/augmented_raw_syscalls.o'
                       \___ Operation not permitted

  (add -v to see detail)
  Run 'perf list' for a list of valid events

   Usage: perf trace [<options>] [<command>]
      or: perf trace [<options>] -- <command> [<options>]
      or: perf trace record [<options>] [<command>]
      or: perf trace record [<options>] -- <command> [<options>]

      -e, --event <event>   event/syscall selector. use 'perf list' to list 
available events
  #

If we bumped 'ulimit -l 128' to get it from the 64k default to double that, it
worked, so use the recently added rlimit__bump_memlock() helper:

  # perf trace -e /wb/augmented_raw_syscalls.o -e open*,*sleep sleep 1
       0.000 ( 0.007 ms): sleep/28042 openat(dfd: CWD, filename: 
"/etc/ld.so.cache", flags: RDONLY|CLOEXEC) = 3
       0.022 ( 0.004 ms): sleep/28042 openat(dfd: CWD, filename: 
"/lib64/libc.so.6", flags: RDONLY|CLOEXEC) = 3
       0.201 ( 0.007 ms): sleep/28042 openat(dfd: CWD, filename: "", flags: 
RDONLY|CLOEXEC)                 = 3
       0.241 (1000.421 ms): sleep/28042 nanosleep(rqtp: 0x7ffd6c3e6ed0)         
                              = 0
  #

Cc: Adrian Hunter <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/builtin-trace.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 1aa2ed096f65..4f0bbffee05f 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -19,6 +19,7 @@
 #include <api/fs/tracing_path.h>
 #include <bpf/bpf.h>
 #include "util/bpf_map.h"
+#include "util/rlimit.h"
 #include "builtin.h"
 #include "util/cgroup.h"
 #include "util/color.h"
@@ -3864,6 +3865,15 @@ int cmd_trace(int argc, const char **argv)
                goto out;
        }
 
+       /*
+        * Parsing .perfconfig may entail creating a BPF event, that may need
+        * to create BPF maps, so bump RLIM_MEMLOCK as the default 64K setting
+        * is too small. This affects just this process, not touching the
+        * global setting. If it fails we'll get something in 'perf trace -v'
+        * to help diagnose the problem.
+        */
+       rlimit__bump_memlock();
+
        err = perf_config(trace__config, &trace);
        if (err)
                goto out;
-- 
2.21.0

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